| Message ID | 1444863507-27463-1-git-send-email-dianders@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 10/14/2015 3:58 PM, Douglas Anderson wrote: > From code inspection, it appears to be unsafe to do a read-modify-write > of PCGCTL in dwc2_port_resume(). Let's make sure the spinlock is held > around this operation. > > Signed-off-by: Douglas Anderson <dianders@chromium.org> > --- > drivers/usb/dwc2/hcd.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c > index af4e4a2..e79baf7 100644 > --- a/drivers/usb/dwc2/hcd.c > +++ b/drivers/usb/dwc2/hcd.c > @@ -1500,6 +1500,8 @@ static void dwc2_port_resume(struct dwc2_hsotg *hsotg) > u32 hprt0; > u32 pcgctl; > > + spin_lock_irqsave(&hsotg->lock, flags); > + > /* > * If hibernation is supported, Phy clock is already resumed > * after registers restore. > @@ -1508,10 +1510,11 @@ static void dwc2_port_resume(struct dwc2_hsotg *hsotg) > pcgctl = dwc2_readl(hsotg->regs + PCGCTL); > pcgctl &= ~PCGCTL_STOPPCLK; > dwc2_writel(pcgctl, hsotg->regs + PCGCTL); > + spin_unlock_irqrestore(&hsotg->lock, flags); > usleep_range(20000, 40000); > + spin_lock_irqsave(&hsotg->lock, flags); > } > > - spin_lock_irqsave(&hsotg->lock, flags); > hprt0 = dwc2_read_hprt0(hsotg); > hprt0 |= HPRT0_RES; > hprt0 &= ~HPRT0_SUSP; > Acked-by: John Youn <johnyoun@synopsys.com> John
diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c index af4e4a2..e79baf7 100644 --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -1500,6 +1500,8 @@ static void dwc2_port_resume(struct dwc2_hsotg *hsotg) u32 hprt0; u32 pcgctl; + spin_lock_irqsave(&hsotg->lock, flags); + /* * If hibernation is supported, Phy clock is already resumed * after registers restore. @@ -1508,10 +1510,11 @@ static void dwc2_port_resume(struct dwc2_hsotg *hsotg) pcgctl = dwc2_readl(hsotg->regs + PCGCTL); pcgctl &= ~PCGCTL_STOPPCLK; dwc2_writel(pcgctl, hsotg->regs + PCGCTL); + spin_unlock_irqrestore(&hsotg->lock, flags); usleep_range(20000, 40000); + spin_lock_irqsave(&hsotg->lock, flags); } - spin_lock_irqsave(&hsotg->lock, flags); hprt0 = dwc2_read_hprt0(hsotg); hprt0 |= HPRT0_RES; hprt0 &= ~HPRT0_SUSP;
From code inspection, it appears to be unsafe to do a read-modify-write of PCGCTL in dwc2_port_resume(). Let's make sure the spinlock is held around this operation. Signed-off-by: Douglas Anderson <dianders@chromium.org> --- drivers/usb/dwc2/hcd.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)